Distribution frames are widely used in the telecommunications industry to interconnect equipment and distribution lines. Typical distribution frames consist of a panel containing a number of connection terminals, such as wire wrapped post or insulation displacement terminals. The terminals are mounted on panels of flat sheet metal members such that the lines entering or leaving a particular distribution frame may be connected directly to the terminals. Typically the distribution lines and the equipment lines are connected to the rear side of the panel, while the cross-connection lines between the terminals are connected from the front side.
Distribution frames conventional in the prior art also include "protection" for operators and equipment. This may be provided either by overvoltage protection circuits or overcurrent protection circuits which are wired between the equipment and distribution lines to protect against transfer from the distribution lines to equipment or equipment operators environmental hazards such as lightning, the effects of which would otherwise be routed directly to electrical equipment interfaced with the lines on the distribution frames.
Distribution frames of this type have many disadvantages. One is that typically it is difficult to access and test individual lines either in the distribution line direction or the equipment direction from the front of the distribution frame panel. Another disadvantage is that many such systems must be wired from one side of the panel and then cross-connected from the other side, making access to the panel durring the wiring process difficult and cumbersome. Third, overvoltage protector devices in the prior art are often expensive to fabricate, and subject to reliability problems. Fourth, systems in the prior art typically have different connection terminals, one set for incoming and outgoing leads and another set for cross-connect functions, which adds to expense and complexity. Fifth, many frames currently on the market comprise large panels, as opposed to a modular approach.